1. Field of the Invention
The present invention relates to board to board modular connectors. More particularly, the present modular connector invention permits the modular assembly of boards.
2. Background of the Related Art
Electrical connectors are used in many types of electronic systems. For example, in many computerized systems, printed circuit boards are joined together through connectors. One piece of the connector is attached to each board. The connector pieces are mated to complete many signal paths between the boards. In addition, the DC power or ground paths are also completed through the connector. The DC paths allow the printed circuit boards to be powered and, if configured appropriately, shield adjacent signal contacts to improve the integrity of signals passing through the connector. It is generally easier and more cost effective to manufacture a system on several printed circuit boards that are then joined together with electrical connectors.
Each half of the connector contains conducting contacts held in an insulative housing. Each contact has a contact region, which makes electrical contact to a contact in the other half of the connector when the connectors are mated. In addition, each contact has a tail portion which extends from the housing and is attached to a printed circuit board. The tail could be either a solder tail, which is soldered to the printed circuit board, or a press-fit tail, which is held by friction in a hole in a printed circuit board. The contact body carries the signal from the contact region to the tail.
One common type of signal contact simply uses a pin as the contact region. Pin contacts generally mate with receptacle type contacts. The contact area of a receptacle type contact is formed from a pair of parallel-cantilevered beams. The cantilevered beams generate a spring force against the pin, ensuring a good electrical contact. Other types of contacts can also used, such as contacts shaped as plates, blades or forks.
Connector housings are often molded from plastic. Initially, connector housings were molded in one piece. However, it is difficult to maintain the necessary tolerances for large surface mount connectors subject to high temperature gradients such that building large connectors from individual modules is easier.